(19)
(11) EP 0 820 882 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
13.05.1998 Bulletin 1998/20

(43) Date of publication A2:
28.01.1998 Bulletin 1998/05

(21) Application number: 97112768.3

(22) Date of filing: 24.07.1997
(51) International Patent Classification (IPC)6: B60C 9/22, B60C 15/06
(84) Designated Contracting States:
AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
Designated Extension States:
AL LT LV RO SI

(30) Priority: 24.07.1996 JP 194937/96
26.05.1997 JP 135473/97

(71) Applicant: Bridgestone Corporation
Tokyo 104 (JP)

(72) Inventor:
  • Ide, Keita, c/o Bridgestone Corporation
    Tokyo 104 (JP)

(74) Representative: Görg, Klaus, Dipl.-Ing. et al
Hoffmann Eitle, Patent- und Rechtsanwälte, Arabellastrasse 4
81925 München
81925 München (DE)

   


(54) Pneumatic radial tire


(57) A pneumatic radial tire in which excellent stability and controllability can be provided and a larger amount of road noise can be reduced. A belt reinforcing layer is disposed outwardly in the radial direction of a tire so as to reinforce the whole portion or the end portions of a tread portion. The belt reinforcing layer is formed by spirally winding a rubber-coated and narrow strip made of a fiber cord/cords around a tire. A pair of bead fillers are disposed directly above bead cores of a pair of bead portions. The cords of the belt reinforcing layer are made of organic fiber cords, and have a 2.7% or less elongation under load of 1.4g/d at the temperature of 50±5°C, and have a 1.5 to 6.0% elongation under load of 0.7g/d at the temperature of 170±5°C. The height L of each of the bead fillers corresponds to 20 to 60% of the cross sectional height T of a tire.






Search report